THE INFLUENCE OF BITUMINIZATION IN KARST CONDITIONS ON THE NATURAL-TECHNOGENIC TRANSFORMATION OF A SMALL RIVER BASED ON GEOCHEMICAL DATA AND BIOTESTING

Abstract

A set of studies consisting of laboratory experiments and field surveys based on geochemical methodsand biotesting allows us to formulate and solve problems related to identifying the consequences of bituminization, natural-technogenic transformation of a small river in karst conditions. A small river acts as a receiver of natural-technogenichydrocarbon flow in the karst region. The chemical composition of the river waters is typical for the conditions of oilfieldtechnogenesis: samples are enriched with chlorides and hydrocarbons. The article presents original materials from experiments on bituminization modeling and field observations on the effect of hydrocarbon doses and concentrations on theoptical density of Chlorella. The study provides information on the content of chemical elements in bottom sedimentsand the results of their biotesting. The experiments established a positive reaction of Chlorella to an increase in oil doses.The quality of bottom sediments in the territory of an oil field is directly or indirectly related to bituminization, whichchanges the ecosystem. The aquatic environment and bottom sediments of the Odinovskaya River sources are enrichedwith oil organic matter and have a positive effect on the vital activity of Chlorella. The lowest optical density of Chlorellais observed in the middle reaches of the small river. The study determined the geochemical series of elements as well asfeatures of their accumulation and migration under technogenic conditions. Arsenic, cobalt, and titanium accumulate inthe bottom sediments, while zinc and manganese migrate. The concentrations of arsenic and lead exceed sanitary standards. Experiments and field sampling for testing with the use of Chlorella showed that technogenic hydrocarbon flowsenhance the heterotrophy of the small river source’s ecosystem. An increase in the density of Chlorella in samples duringtesting can be diagnosed as technogenic organic pollution. Under natural-technogenic conditions, Chlorella also reacts toan increase in hydrocarbon content, as in the experiment. It is possible and advisable to diagnose bituminization by theincreased optical density of Chlorella.